Ivan Shishkin, Pine Forest

Weekly Problem Design Contest

Results announced

Pascal's Ghost

Starts Saturday, September 12, 2026 Deadline Friday, September 18, 2026 · Paris time Prize 300 reputation points

Create a problem on the theme “Pascal’s Ghost.”

Your problem may be inspired by Blaise Pascal, his work, or mathematical ideas associated with him: Pascal’s triangle, combinatorics, games of chance, or even projective geometry…

The “ghost” may be a hidden theme or, on the contrary, an actual ghost.

Feel free to interpret the theme however you like!

How entries are judged

  • Fit to the weekly theme
  • Originality
  • Mathematical interest
  • Clarity
  • Presentation

Rules

One entry per person. You may edit your problem until Friday at 23:59, Paris time. Admins select one winner and may also award honorable mentions. Translations of the same problem count as one entry.

Results announced

Entries

6
50Le carré de Pascal et son grand théorème ?FRDattier Honorable mention40Inversion de PascalFRSequoia80Le spectre de PascalFRaraucaria araucana Winner50Théorème de l’étoile de DavidFRdarktoaster50Le pari du fantômeFRvisitor60Attention ce problème pourrait devenir une malédictionFRmathman

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